There are industrial vehicles which utilize arms to perform various tasks. For example, a skid steer loader or compact track loader utilizes an arm on each side of an enclosure in which a user sits, or cab, to raise and lower a work implement, e.g. a bucket. By way of another example, an excavator, telehandler and mobile crane utilize a single arm on one side of a cab to raise and lower a work implement. Other industries also use vehicles with one or more lift arms and a cab such as delimbers, feller bunchers, and harvesters.
Because the lift arms function, e.g. raise and lower, on one or both sides of the cab, certain safety standards and/or industry practices require that the cab be guarded and/or enclosed on the side(s) adjacent the lift arm(s) to prevent the user or operator in the cab from extending an arm, or any other body part, into the path of the lift arm(s) and causing bodily harm to the operator. Safety standards and/or industry practices also require that such an enclosure be able to withstand certain forces, e.g. impact resistance.
Currently, such construction vehicles enclose the cab in one of two ways. Some such construction vehicles enclose the side(s) of the cab adjacent the arm(s) with a cage. Cages are typically made from metal, e.g. steel. Some cages are made from a series of metal materials, such as dowels or bars, connected together to form a grid or lattice, while others are punched from a larger sheet of material. In either case, the openings of the cage are properly sized to prevent an operator from putting an extremity through, into the path of a lift arm.
Cages have a number of advantages, including being lower cost and allowing ventilation of the cab and an operator of the vehicle to communicate with people outside of the vehicle and vice versa. However, cages also have a number of disadvantages including impairing vision, allowing dust and debris to enter the cab and exposing the operator to the elements, e.g. during extreme cold or warm temperatures. These disadvantages can affect the operator's performance and safety.
Other such construction vehicles enclose the side(s) of the cab adjacent the arm(s) with a solid clear sheet of material, such as glass or polymers including polycarbonate or acrylic, that encloses the entire side(s) adjacent the arm(s). The material is durable and strong enough to prohibit breakage in extreme conditions. Use of a solid clear sheet of material, such as polycarbonate, has a number of advantages that are largely the disadvantages of a cage. However, using a solid clear sheet of material also has many disadvantages including being more costly, impeding the ability for an operator to communicate with people outside of the vehicle and vice versa, and preventing ventilation. These disadvantages can also affect the operator's performance and safety.
Some construction vehicles have attempted to combine a cage with an operable window. Examples are discussed in U.S. Pat. No. 8,091,955 and published European Patent Application Number 1,066,998. Such combinations do gain the benefits from being able to open and close a window, but suffer from being more costly, having both a cage and window structure, while still impairing the vision of the operator. Cleaning the exterior of the window, between the window and the cage can also be difficult and time consuming.
As such, there is a need for a cost effective cab enclosure that is able to withstand certain forces acting on it, can be selectively opened and closed and prevents an operator from being able to put his or her self in the path of the lift arm(s) all while not impairing the vision of the operator.
It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can lead to certain other objectives. Other objects, features, benefits and advantages of the present invention will be apparent in this summary and descriptions of the disclosed embodiment, and will be readily apparent to those skilled in the art. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying figures and all reasonable inferences to be drawn therefrom.